Risk Factors and Surgical Treatment for Symptomatic Adjacent Segment Degeneration after Lumbar Spine Fusion

Abstract

Objective : The present study analyzed the risk factors, prevalence and clinical results following revision surgery for adjacent segment degeneration (ASD) in patients who had undergone lumbar fusion. Methods : Over an 8-year period, we performed posterior lumbar fusion in 81 patients. Patients were followed a minimum of 2 years (mean 5.5 years). During that time, 9 patients required revision surgery due to ASD development. Four patients underwent autogenous posterolateral arthrodesis and extended transpedicle screw fixation, 4 patients underwent decompressive laminectomy and interspinous device implantation, and 1 patient underwent simple decompression. Results : Of the 9 of patients with clinical ASD, 33.3% (3 of 9) of patients did not have radiographic ASD on plain radiographs. Following revision surgery, the clinical results were excellent or good in 8 patients (88.9%). Age > 50 years at primary surgery was a significant risk factor for ASD development, while number of fusion levels, initial diagnosis and type of fusion were not. Conclusion : The incidence of ASD development after lumbar surgery was 11.1% (9 of 81) in this study. Age greater than 50 was the statistically significant risk factor for ASD development. Similar successful clinical outcomes were observed after extended fusion with wide decompression or after interspinous device implantation. Given the latter procedure is less invasive, the findings suggest it may be considered a treatment alternative in selected cases but it needs further study.

Adjacent segment degeneration after single-segment PLIF: the risk factor for degeneration and its impact on clinical outcomes

“…Some authors believe that adjacent segment degeneration is related to age, sex, length of fusion segments, spinal sagittal alignment, and menopause [2,19,20]. Cho et al [21] found that elder patients was associated with higher incidence of adjacent segment degeneration after PLIF, therefore he thought that age was an important risk factor. Aota et al [22] found that the incidence of adjacent segment degeneration might increase significantly in patients older than 55 years.…”

Lateral lumbar interbody fusion with unilateral pedicle screw fixation for the treatment of adjacent segment disease: a preliminary report

“…The non-significant decrease in ODI score from 48.5±12.0 to 40.0±17.4 during final followup may suggest a worse natural history of spine pathology in ASD patients. It is possible that patients requiring surgery for ASD may be biased towards a natural history that is (19). Direct comparison of surgical techniques for treatment of ASD should be performed.…”

Rigid fixation of the lumbar spine alters the motion and mechanical stability at the adjacent segment level

“…[3,6,8,9,12,16,17] Although recent biomechanical studies have shown that a number of spinal devices can be used for rigid fixation and fusion at the treated level, little attention has been focused on the adjacent segment instability. [2,5,6,8,12,13,[16][17][18] The present study focused on the adjacent segment instability. As adjacent segment mobility increased, the anterior and posterior structures maintained stability and prevented instability.…”

“…The second theory posits that degeneration of the adjacent segment is indicative of the natural degenerative course of an aging disc. [3,[7][8][9]13,14] In this study, we aimed to investigate the mechanical behavior and instability of the adjacent segment following rigid fixation.…”